Low-cost printers typically ship with a relatively small amount of RAM and no persistent storage (either hard disk drive (HDD), solid state disk (SSD), memory cards, or the like). That means that although many documents can be printed using streaming page description languages (PDLs) such as PostScript, Printer Control language (PCL), and some forms of the XML Paper specification (XPS), an especially complex document may fail to print because it would require more RAM than is available in the device. Furthermore, documents delivered in non-streaming PDLs (such as PDF and some forms of XPS) must be available to the renderer in their entirety before they can be processed. Thus, they must be stored in the printer. If the printer only has RAM for storage, that reduces the working memory available for processing, which means that even simple documents may fail to print. Any file that's simply too large to be stored locally cannot be processed at all.